Pink bleed.

I had sex a week ago unprotected (both clean and provided proof) I am on the mini pill and taken it at the exact time everyday prior and after sex so pretty sure I am not pregnant. However I’m due on my period in 15 days but Ive been experiencing a light bleed only visible when I wipe which started yesterday night, however the more frequent I wipe the less blood is present, I also checked with a mirror to see if everything was good but I cannot see any blood only discharge which is normal for me. the bleed is pinkish mixed in with my urine. I have no symptoms like burning, itching, stomach pains etc. So I am just wondering if this is possibly spotting or a break through bleed.